Okay, confirmed. If you leave the charger cable plugged into the car then the 12V battery drains.
1 day - 12 V battery okay
1.5 days - 12 V battery marginal (car may give weird warnings but can be made to work)
2 days - 12 V battery is dead.
This is quite a lot of current drain with a little...
Your description of the problem is perfect the warning suddenly on the main screen, then totally off, except for little fast blinking side lights. About 500 miles on my car so far. I last drove on Friday, tried to drive this Sunday night. And the 12V battery died. I can't think of anything I did...